The son of a Queens couple gunned down as they slept became so withdrawn and depressed after their murder it was as if “he died inside,” a family friend testified yesterday.

Jurgita Vaitkiene said that Lukas Dainys, who was 9 when his parents were shot dead in 1997, “was like a changed child.”

Dainys’ mother, Yurate Dainene, and his father, Rimgaudas Dainys, were each shot once in the head on March 30, 1997, in their Astoria apartment. Lukas Dainys was sleeping in the room next door and woke up after hearing the shots.

He is expected to testify today that he saw his mother’s ex-lover, Abel Rosas, run past his room moments after the shooting.

This is the third trial for Rosas.

The first resulted in a hung jury in 1998. Lukas Dainys’ testimony in the second trial that he saw Rosas fleeing the apartment helped get a conviction, but it was overturned after the discovery of a prosecution memo that said he only saw a “shadowy figure” that looked like his mother.

Vaitkiene testified yesterday that Lukas Dainys “was very scared” and “couldn’t sleep” without sleeping pills in the days following the incident.